In general, examples of measuring instruments include a flowmeter, a thermometer, a barometer, and a spectrometer (densimeter, densitometer), and those measuring instruments each have a function of constantly observing a measurement result of the measuring instrument. In addition, in the measuring instrument, various sensors perform state monitoring, that is, monitoring regarding in what condition the measuring instrument is being operated.
Examples of the flowmeter include a positive displacement flowmeter and a Coriolis flowmeter. The positive displacement flowmeter includes a measuring chamber having a rotor, which rotates in proportion to the volume of a fluid to be measured flowing through a flow tube, provided therein, and determines the flow rate based on the rotation of the rotor rotating in proportion to the volume of the fluid to be measured flowing into the measuring chamber. The Coriolis flowmeter is a mass flowmeter in which one end or both ends of a flow tube through which a fluid to be measured is flowing are supported, and which utilizes a fact that a mass flow rate is proportional to a Coriolis force acting on the flow tube (which is a tube in which oscillation is to be generated) when oscillation is generated in a direction perpendicular to a flow direction of the flow tube with the supported points being fixed.
Further, the spectrometer such as a densimeter or a densitometer uses an analyzing device configured by an ion source, an analyzer, and a detector, thereby ionizing a compound by the ion source and analyzing the compound based on a spectrum.
The thermometer, which is an instrument for measuring temperature, measures the temperature by utilizing such a physical phenomenon as a change in property caused by temperature change. Further, the barometer is a device for measuring a pressure, which is a force acting per unit area.
Those measuring instruments sometimes suffer from problems. When a problem has occurred to such a measuring instrument, a field engineer comes to inspect the measuring instrument. When the field engineer inspects the measuring instrument, he/she uses a technique of troubleshooting.
The technique of troubleshooting is a method in which the cause of the problem is found by excluding possible causes of the problem, and such a method is adopted in a field such as system administration. Such a technique of troubleshooting is used, for example, in a case where a measuring instrument which has been in operation suddenly stops operating and measurement cannot be performed. In the troubleshooting, components constituting the system are checked one by one.
Description is given by taking as an example the Coriolis flowmeter, which is a typical flowmeter among measuring instruments. The Coriolis flowmeter is a mass flowmeter in which one end or both ends of a flow tube through which a fluid to be measured is flowing are supported, and which utilizes the fact that a mass flow rate is proportional to the Coriolis force acting on the flow tube (which is a tube in which oscillation is to be generated) when oscillation is generated in a direction perpendicular to a flow direction of the flow tube with the supported points being fixed. The Coriolis flowmeter is well known, and the shape of the flow tube in the Coriolis flowmeter is classified into two major types of a straight tube type and a U-shaped tube type.
Then, the Coriolis flowmeter, which is a typical flowmeter among measuring instruments, is a mass flowmeter in which a measuring tube, through which a fluid to be measured flows, is supported at both ends thereof, and when a central portion of the supported measuring tube is alternately driven in a direction perpendicular to a support line, a phase difference signal proportional to a mass flow rate is detected between the supported portions positioned at symmetric positions of the measuring tube at its both ends with respect to the central portion. The phase difference signal represents an amount proportional to the mass flow rate, but assuming that a drive frequency is constant, the phase difference signal can be detected as a time difference signal between observation positions of the measuring tube.
When the frequency for alternately driving the measuring tube is made equal to the eigen frequency of the measuring tube, a constant drive frequency can be obtained according to the density of the fluid to be measured, which enables driving the measuring tube with small drive energy. Accordingly, in recent years, it has been a common practice to drive the measuring tube at the eigen frequency, and the phase difference signal is detected as the time difference signal.
When a problem has occurred to a measuring instrument, and a field engineer comes to inspect the measuring instrument, many cases of the troubleshooting performed by the field engineer for the flowmeter have no reproducibility. Accordingly, the field engineer estimates the cause of the problem by his/her experiences. As a result, depending on the field engineer's skill, he/she may mistakenly estimate the cause of the problem and set a wrongly-estimated cause, resulting in a longer time period required for the solution to the problem.
A manufacturer of products sets a maintenance period in advance for its own delivered products, and, for a given period of time after the delivery, guarantees the securing of replacement parts or the provision of maintenance for the users of the products. The maintenance period of the products is determined based on a suppliable period of the replacement parts, the life of the parts, or the like.
For example, JP 2005-327201 A proposes a maintenance support program for performing a reliability analysis on an apparatus based on equipment maintenance information including failure information, replacement information, update information, and the like of the apparatus, which are fed back from the place of operation of the apparatus (including various units, such as a product, a product type, a part, a part type, equipment, a system, a device, a product model, a part model, and a plant), and on shipping information of the apparatus, including shipping date information, design information, and the like of the apparatus.
The maintenance support program of JP 2005-327201 A is for extracting data in a desired combination of items including, for example, a product type, apart type, and a model, which are examples of identification information of the apparatus, and a business type and a customer name, which are examples of customer identification information of the apparatus, and for executing calculation or the like of a failure occurrence probability density function or an unreliability function with respect to a result of the data extraction.
Further, considering the fact that, with the maintenance support program described in JP 2005-327201 A, while the reliability of the product can be improved by setting a maintenance timing for the apparatus or the part of a set model, it is impossible to perform prioritization for determining an apparatus to be subjected to the maintenance, JP 2009-178713 A proposes a control system for water treatment facilities which can continuously support the setting of a maintenance and inspection frequency for equipment of a membrane treatment facility in order to supply tap water or regenerated water of stable quality and quantity by water treatment using a membrane.